1. Field of the Invention
This invention relates to a fire hydrant locking device which is easy to install and very effective.
2. Description of the Realted Art Including Information Disclosed Under 37 CFR .sctn..sctn.1.97-1.98
The unauthorized use of fire hydrants constitutes a great fire risk to dwellings and businesses due to low pressure in the system. There is also a waste of water which is costly and a severe problem during droughts. Another problem is the theft of water from fire hydrants for sale or recreational uses. It is therefore important to develop a locking device for fire hydrants which prevents unauthorized use of fire hydrants. Indeed a considerable body of prior art attempts to address this problem but the problem still exists and this invention is designed to provide a satisfactory cost saving solution.
The prior art includes U.S. Pat. No. 5,722,450 to JULICHER which relates to a tamper resistant construction for hydrants employing a shroud rotatably mounted on an end portion of the hydrant nut actuating body. In another approach, U.S. Pat. No. 5,588,460 to MENESES discloses an internally threaded tubular shield about the valve stem and a wrench having a pentagonal tubular socket to fit the keyway and the valve stem.
U.S. Pat. No. 5,549,133 to SIGELAKIS discloses a security device clamped between an outlet port of the hydrant and a cap for covering the outlet port while U.S. Pat. No. 5,520,210 to BARTON discloses a protective shield for a fire hydrant operating stem. The shield includes an inner ring with a peripheral groove which carries a snap ring. A standard authorized tool may be used in connection with the device.
U.S. Pat. No. 5,469,724 to POLLARD appears to be a standard locking device enclosing the operating nut of the hydrant. U.S. Pat. No. 5,383,495 to KENNEDY discloses a security hydrant cap having a domed body adapted to be removed only with a specialized tool and a surrounding slip ring substantially over the body. U.S. Pat. No. 4,033,501 to STEHLING discloses a fire hydrant cap and actuating tool which includes a gripper which fits under a slip ring to prevent the tool from slipping a spanner wrench and a hexagonal socket with a screw for gripping rounded off valve stems.
None of the above patents disclose the advantageous locking system proposed by applicant for fire hydrants. The considerable number of recent patents shows the interest and need in this area which the present invention is designed to meet.